Bed bugs, also known as wall lice, bite localized lumps that may manifest as redness, swelling, warmth, and itching. Bed bug bites can lead to a localized allergic reaction, causing insect bite dermatitis, also known as papular urticaria. It is often accompanied by a localized lump, which may be round or fusiform, and is usually combined with localized redness, heat, and intense itching, and may be accompanied by localized rounded or rough, uneven, papular symptoms. Treatment is mainly based on anti-allergy and symptomatic therapy, including the use of chlorpheniramine maleate, loratadine and other drugs, and at the same time, can be applied with topical medications such as glycerine lotion, halometasone ointment and other topical medications. It is also recommended that bedding, clothes, bed boards, mattresses, etc. be thoroughly cleaned and exposed to the sun. If the above symptoms of redness, swelling and itching occur, it is recommended to go to the hospital in time and follow the medical treatment. The above medications should be used under the guidance of a clinician, and should not be used on their own.